A "Mecha" is a giant warrior robot, sometimes with one or more humans inside it, and sometimes on its own. They were invented by the Japanese anime-makers, and now they are everywhere. These warrior robots fight titanic battles in the "Warhammer" tale that I am currently reading. This one is not one of the truly gigantic ones, it is a more humanoid model used for quick assaults. I have always thought that humanoid mechas would not be much good on the battlefield because they can be knocked down so easily by attacking the legs. But they are so cool that you have to have them.
"Warhammer Battle Mecha" is Photoshop, 7" x 10", April 3, 2011.